Re: [PACTH v3 3/5] tpm_spapr: Support suspend and resume

[Marc-André Lureau]

Hi

On Wed, Dec 11, 2019 at 8:27 PM Stefan Berger
<address@hidden> wrote:
>
> Extend the tpm_spapr frontend with VM suspend and resume support.
>
> Signed-off-by: Stefan Berger <address@hidden>
> ---
>  hw/tpm/tpm_spapr.c | 42 +++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/hw/tpm/tpm_spapr.c b/hw/tpm/tpm_spapr.c
> index c4a67e2403..d9153bd95c 100644
> --- a/hw/tpm/tpm_spapr.c
> +++ b/hw/tpm/tpm_spapr.c
> @@ -87,6 +87,8 @@ typedef struct {
>      TPMVersion be_tpm_version;
>
>      size_t be_buffer_size;
> +
> +    bool deliver_response; /* whether to deliver response after VM resume */
>  } SPAPRvTPMState;
>
>  static void tpm_spapr_show_buffer(const unsigned char *buffer,
> @@ -339,9 +341,47 @@ static enum TPMVersion tpm_spapr_get_version(TPMIf *ti)
>      return tpm_backend_get_tpm_version(s->be_driver);
>  }
>
> +/* persistent state handling */
> +
> +static int tpm_spapr_pre_save(void *opaque)
> +{
> +    SPAPRvTPMState *s = opaque;
> +
> +    s->deliver_response = tpm_backend_finish_sync(s->be_driver);
> +    /*
> +     * we cannot deliver the results to the VM since DMA would touch VM 
> memory
> +     */
> +
> +    return 0;
> +}
> +
> +static int tpm_spapr_post_load(void *opaque, int version_id)
> +{
> +    SPAPRvTPMState *s = opaque;
> +
> +    if (s->deliver_response) {
> +        /* deliver the results to the VM via DMA */
> +        tpm_spapr_request_completed(TPM_IF(s), 0);

Why isn't it enough to rely on tpm_spapr_request_completed callback
being called during pre-save when tpm_backend_finish_sync() is called?
(like tis & crb)

> +    }
> +
> +    return 0;
> +}
> +
>  static const VMStateDescription vmstate_spapr_vtpm = {
>      .name = "tpm-spapr",
> -    .unmigratable = 1,
> +    .version_id = 1,
> +    .minimum_version_id = 0,
> +    .minimum_version_id_old = 0,
> +    .pre_save = tpm_spapr_pre_save,
> +    .post_load = tpm_spapr_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_SPAPR_VIO(vdev, SPAPRvTPMState),
> +
> +        VMSTATE_UINT8(state, SPAPRvTPMState),
> +        VMSTATE_BUFFER(buffer, SPAPRvTPMState),
> +        VMSTATE_BOOL(deliver_response, SPAPRvTPMState),
> +        VMSTATE_END_OF_LIST(),
> +    }
>  };
>
>  static Property tpm_spapr_properties[] = {
> --
> 2.21.0
>
>


-- 
Marc-André Lureau